The present invention relates to the art of wheelchair and, more particularly to motor wheelchairs.
Wheelchairs powered with reversible electric motors are used to provide motorized mobility to persons. Examples of powered wheelchairs are disclosed by G. G. Goertzen, N. J. Curran and J. H. Molnar in U.S. Pat. No. 5,575,348 and J. B. Richey, T. D. Wakefield and A. D. Wainscott in U.S. Pat. No. 5,094,310. These wheelchairs have frames supported on wheels for rolling movement. Electric motors coupled to batteries drive speed reducing gear boxes which transmit torque to the drive wheels of the wheelchair to move the wheelchair. The efficiency of the power of the motors transmitted to the drive wheels in reduced by the power required to operate the speed reducing gear boxes. Seat units having side arm rests are mounted on the frames to accommodate persons in need to the use of wheelchairs. The seat units have open fronts providing access to the seat and back rests. The arm rests prevent lateral admittance of the persons to the seat units. Electronic control units carried by the wheelchair regulate power driven operation of the drive motors. Joy sticks located adjacent the arm rests are used by persons seated in the seat units to actuate the control units which control the operation of the motors to move the steer the wheelchair. The electric motors, speed reducing gear boxes, electronic control units and battery re-chargers are located below the level of the seat units and are exposed to environmental elements, such as dirt, mud, water, ice and snow.
The invention comprises a wheelchair having a novel seat assembly, enclosed electric motor drives, and foot rests. The wheelchair has a frame with side frame members rotatably supporting drive shafts for wheels driven by the electric motor drives to move the wheelchair. A casing mount on the side frame members encloses the electric motors, motor drives to shield the motors and drives from the external environment including water, dirt, mud, ice, and snow. The batteries and electronic control unit connected to the motors are also located within the casing. The motor drives have power transmission systems located within the casing that efficiently transfers power from the electric motors to the drive wheels.
The seat assembly has a base and side members hinged to the base for selective movement to upright and down positions. Arm rest are mounted on the side members. Releaseable locks hold the members in the upright members. When the locks are released the side members and arm rests can be pivoted to down positions to allow lateral access to the seat of the seat assembly. A person can be admitted to the seat assembly from the front or either side of the seat assembly. The front of the base of the seat rest in pivotally mounted on the frame to allow the base to pivot about a transverse horizontal axis. Shock absorbers having coil springs connected to the rear of the base and frame cushion the seat assembly. The shock absorbers extend downwardly and rearwardly from the base to provide non-linear compression forces the absorb impact and bounce movements of the person in the seat assembly. This reduces stresses and strains on the person""s back.
A pair of foot rests secured to the frame extend downwardly from the front of the seat assembly to accommodate the legs and feet of the person seated in the seat assembly. Each foot rest has first and second square tubular members with the second member telescoped in the first member. Fasteners hold the members together in a selected position to adjust the length of the foot rest to fit the person in the seat assembly. A platform pivotally mounted on the lower end of the second member is retained in a generally horizontal or slightly inclined position to support a persons foot. The platform can be folded up against the members so that it does not interfere with the front seating of the person in the seat assembly.